The objective of this project will be to study the mechanisms of transformation and fate of toxic substances primarily in coastal environments. This project will focus on understanding the molecular mechanisms by which metal contaminants are transformed from soluble phases to insoluble phases and to evaluate the contribution from different physiological groups of bacteria in this process. Experiments will center on re-expression of genes and characterization of multi-copper oxidase- like proteins involved in catalyzing Mn (II) oxidation in different bacterial groups. In addition Dr. Tebo has identified several novel bacteria that resist the toxic levels of Cr(VI) and grow with Cr(VI) as an electron acceptor. The second part of his project will examine the biochemical basis for Cr(VI) reduction in these novel Cr(VI)-reducing bacterial and study the regulation of Cr(VI) and the expression of other genes in response to Cr(VI).